Electronic devices, such as smart phones, smart watches, wrist bands and the like, can include applications (apps) that enable tracking of physical activities. This can include, for example, distance measurements (e.g., how far did a person walk or run), average speed measurements (e.g., how fast did the person walk or run), heart rate measurements, calories burned, etc.
To detect physical activity, the electronic device typically includes an accelerometer that can detect movement of the electronic device and, thus, of the user. For example, an electronic device in the form of a smart watch may be worn on the user's wrist. As the user performs a physical activity, the user's arms (and thus the electronic device) undergo motion characteristic of the activity. Data corresponding to the characteristic motion can be detected by the accelerometer and analyzed within the electronic device to determine the type of activity as well as any information related to the activity.
A problem with conventional methods for detecting user activity is that they hinge on motion of the part of the body to which the electronic device is attached (worn) or held. Typically, electronic devices are worn on the wrist (smart watch, smart band) or upper arm (e.g., mp3 player, smart phone). Such location of the electronic device can be problematic when the particular activity does not involve motion (or significant motion) of the arm. For example, when bicycling the user's arms are relatively stationary and, thus, detection of physical activity while biking can be difficult.